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Updated: May 16, 2026
A Syngeneic Mouse Model of Metastatic Renal Cell Carcinoma for Quantitative and Longitudinal Assessment of Preclinical Therapies
Published on: April 12, 2017
[Small renal cell carcinomas and synchronous metastases]
Petur Solmar Gudjonsson1, Elin Mariusdottir, Helga Bjork Palsdottir
1University of Iceland, Iceland.
Objective:
The incidence of renal cell carcinoma (RCC) is rising in part due to small tumors (≤4cm) detected incidentally with abdominal imaging. Survival for small RCCs has been regarded as favorable and guidelines recommend partial rather than total nephrecteomy. We studied the frequency of synchronous metastasis in patients with small RCCs in Iceland.
Materials And Methods:
A retrospective study on 257 patients with RCC ≤4cm out of 1102 RCC patients diagnosed in Iceland 1971-2010. Patients with metastasis were compared to those with localized disease. Hospital charts were reviewed and histology, TNM-stage and disease-specific survival compared between groups.
Results:
The proportion of small tumors increased from 9% in 1971-1980 to 33% in 2001-2010 (p<0,001) and incidental detection increased from 14% to 39% during the same period. Out of the 257 patients with small RCCs, 25 (10%) had synchronous metastases, most frequently in lungs or bones. Patients with metastases were on average 1.9 years older, their tumors were 0.2 cm larger and more often located in the right kidney, their hemoglobin was lower and nuclear grade and T-stage higher. Histology was similar in both groups. Five-year survival of patients with and without metastases was 7 vs. 94%, respectively (p<0.001).
Conclusions:
One out of ten patients with small RCC has synchronous metastases at diagnosis. This is higher than in most previous reports that usually include surgical patients only. Patients with metastases are significantly older, more often symptomatic, their tumor are larger and their prognosis worse. Our results indicate that small RCC is a potentially systemic disease at diagnosis that has to be taken seriously.
Insights
Synchronous metastases occur in 10% of small renal cell carcinoma (RCC) cases. This indicates small RCC can be a systemic disease, necessitating serious consideration at diagnosis.
Area of Science:
- Oncology
- Urology
- Pathology
Background:
- Renal cell carcinoma (RCC) incidence is rising, with more small tumors (≤4cm) detected incidentally.
- Guidelines recommend nephrectomy for small RCC, assuming favorable survival.
- The frequency of synchronous metastasis in small RCCs has not been well-established.
Purpose of the Study:
- To investigate the frequency of synchronous metastasis in patients diagnosed with small renal cell carcinoma (RCC) in Iceland.
- To compare characteristics and survival between small RCC patients with and without synchronous metastasis.
Main Methods:
- Retrospective study of 257 patients with RCC ≤4cm from 1102 RCC patients diagnosed in Iceland (1971-2010).
- Comparison of patients with metastasis versus localized disease.
- Review of hospital charts for histology, TNM-stage, and disease-specific survival.
Main Results:
- The proportion of small tumors increased significantly from 9% to 33% (2001-2010).
- 10% (25/257) of small RCC patients had synchronous metastases, primarily in lungs or bones.
- Patients with metastases were older, had larger tumors, higher nuclear grade and T-stage, and significantly worse 5-year survival (7% vs. 94%).
Conclusions:
- Synchronous metastasis is present in one out of ten small RCC patients at diagnosis.
- Small RCC should be considered a potentially systemic disease, even when detected incidentally.
- Findings challenge the assumption of universally favorable prognosis for small RCCs.
